I am very new to bettas and only have 1. I know he is a male because of his fins. I keep him in a half a gallon tank with a small filter i feed him at least 5 pellets a day and sometimes more, and the tank consist of pebbles and small bamboo plant (which creates algae which i think he eats). He likes the bubbles from the filters and is pretty active. Recently he doesn't eat anything, i think its because of the room temp. i used to keep him in the living room where it was warm now i keep him in my room where its a bit cooler. before this happened he started flaring at his food then a day later stopped eating! Recently he likes to be around the roots of the plant even goes under them... should i be worried? is he okay?

How long have you had him and what's your water change schedule like? Ammonia builds up fast in such a small tank and even with a filter, you still need to do water changes. Also, you may be feeding him too much. How big are the pellets? And is there any place for him to hide, like a cave or something?

He may be too cold but a .5 gallon is hard to heat. If he was in something that was at least 2 gallons, you could then get a 25 watt heater for him. They do make ones for bowls and such but they have to be monitored as they do not shut off when the temp gets to hot.

If you can answer these, that will give us more information to help youHousing
What size is your tank?
What temperature is your tank?
Does your tank have a filter?
Does your tank have an air stone or other type of aeration?
Is your tank heated?
What tank mates does your betta fish live with?

Food
What type of food do you feed your betta fish?
How often do you feed your betta fish?
MaintenanceHow often do you perform a water change?
What percentage of the water do you change when you perform a water change?
What type of additives do you add to the water when you perform a water change?

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and TreatmentHow has your betta fish's appearance changed?
How has your betta fish's behavior changed?
When did you start noticing the symptoms?
Have you started treating your fish? If so, how?
Does your fish have any history of being ill?
How old is your fish (approximately)?

FOOD: hikari betta bio-gold, everytime i check up on him (but he hasn't been eating recently)
MAINTENANCE: change water every 2weeks, all of it, no additives are added
SYMPTOMS AND TREATMENT: appearance hasn't changed, has a sluggish behavior, about a week ago, no treatment started, never ill, approx a year old

I'd highly recommend at least a gallon for your betta. Also, if you must use a half gallon for the time being, you absolutely need to change the water daily. No doubt about that. For my one gallon tanks I do 50 and 100% every week, works lovely, and my fish are healthy. Also, keeping the water warm is a must. I'd highly rocommend a heater, dear. They do so much better in warm water. You might try some new food too, I use Topfin Betta Bites. My little guy loves them. Hikari Bio-Gold I've heard hasn't done so well with peoples fish. Also, do you use conditioner? Because that's a must as well, hun if it's not spring water, or something like that.

As said above if you don't use well water you need to add dechlorinator. One thing may be ammonia posioning because of the water changes. I would advise 100% water change everyother day. Ammonia comes from the fish naturally, in the poop and also they release ammonia from their gills when they breath. If you can get a bigger tank or bowl I would strongly recommend it. Bettas do jump so if you get a bowl put plastic wrap over it and poke holes in it so fresh air can come in. I will contact myates as she knows WAY more than me.

I am wanting to think that there are a couple of different things at play here..

Firstly, in a half gallon I would suggest 2 50% and 1 100% water change per week using water conditioner for full volume of the tank. As mentioned before, ammonia and nitrates will build up rather quickly in a small tank such as that- and in time it will catch up to your little guy in ways of ammonia/nitrate poisoning which is deadly. Unless you are using well water and know for sure that there is no chlorine and other harmful things in the well water- very wise to use water conditioner, regardless of water source, especially in that size of a tank.

You moved him to a different room- that alone could be cause for him being lethargic as well. If the living room was more active with people walking around, and the bedroom not as active then he may feel stressed and in a sense.. lonely.
I have a boy that was at my desk, moved him to my shelf unit across the room- he started hiding and being lethargic most of the time until I returned him next to my tank where he could see me. Bettas do recognize us around them and sometimes use us for company. The surroundings he (and yours) got used to changed all of a sudden, it can affect their stress/comfort level.
So yours not eating may just be until he adjusts to his new surroundings.

As for the temp- they can live in cooler temps, but it will catch up to them and would cause lethargy, lowered immune system, and slower metabolism- which will in turn mean less food intake.
There really is no safe way to heat a container that small steady without any fluctuations though. Fluctuations could cause them to go into shock- so the temp must stay warm and even.

Is there a way to post a pic of your tank? I'm trying to imagine a half a gallon with a bubbler, filter and a bamboo plant in there, and yet still have enough room to actually swim around like a fish. Bettas are like any other fish you see in tanks, and need room to swim. They can live in unfavorable conditions, but it normally catches up to them in either illnesses or lesser life span. I would recommend upgrading to at least a gallon.

As for the bamboo- as long as there are no leaves or any part of the bamboo other then the bottom stalk in the water then it should be safe. Your betta isn't eating the algae off of it, as they are insectivores. Most likely he is looking for something to do, or just being curious.

Plastic/seran wrap is a good idea- when using a heater, covering up the tank with it, taping it to the sides so it does not touch the water, and poking a few holes in it will help build up humidity on the water surface, which in turn keeps the labyrinth organ working good and healthy.

If you have any more questions, please feel free to ask. We don't mean to harp on you, but rather try to help and teach, so in turn it helps your little guy :)

Well I just got a new Betta two days ago, she's a girl. I Just moved her to my room so she can be warmer. She lives in a One Gallon Fish Bowl. I don't have a heater as it does not fit in the bowl. I did put a thermometor is 74.23 up to now it has been that tempature for a while. I give her BettaMin Flakes Tropical Medly (Tetra is the marketer) I feed her ounce a day because she is still so small. I also used BettaSafe Water Conditioner when I first put her in her new fish bowl. I also got her yesterday an aquarium logg with plants fake plants, that are soft so she has a place to hide in and have to herself. And I bougth Aquarium Salt (Junggle is the marketer) just to be safe. I will be changing the water ounce , every week. She seems to be doing fine up to now. She is the only fish in there though, no more than one. Is this alright? I've been doing all I can on reaserch and everything in my power and space to do the very best i can for her. I just feel with all I've read is not enough. I'll post a pic of her soon.

Yes she does have a cover and has a light and it does have a hole where I feed her and she gets air from. I looked for a heater but they are for 2 gallons up to 5 gallons. So 2x a week you say? Hmm I thought it was ok with ounce a week every week. She seems active anf fine for now but thanks.